Study of ATRX mediated telomere maintenance in neuroblastoma by using genome editing technology (CRISPR/Cas9)

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K15256
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 50010:Tumor biology-related
• Research Institution: Research Institute for Clinical Oncology Saitama Cancer Center
• Principal Investigator: AKTER JESMIN 地方独立行政法人埼玉県立病院機構埼玉県立がんセンター(臨床腫瘍研究所), 臨床腫瘍研究所, 技師 (70795830)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 神経芽腫 / ATRX / TP53 / FANCD2

Outline of Final Research Achievements

Genetic aberrations are frequently present in the ATRX gene in older high-risk neuroblastoma (NB) patients with very poor clinical outcomes. Its loss-of-function strongly linked to replication stress (RS) and DNA damage through G-quadruplex (G4) DNA secondary structures. However, limited information is available on ATRX alteration-related NB tumorigenesis. We herein knocked out ATRX in MYCN-amplified (NGP) and single copy (SK-N-AS) NB cells with wild-type (wt) and truncated TP53 at the C terminus, respectively, using CRISPR/Cas9 systems. We revealed that ATRX depletion in TP53 wt NB cells was associated with an increased frequency of DSBs and a subsequent RS-induced DNA damage response, which was impaired by the loss of p53 through the activation of G4 DNA helicases or the FA DNA repair pathway protein, FANCD2. Therefore, it indicates that p53 deficiency limits ATRX loss-induced RS/and genome instability in NB cells by regulating DNA repair mechanisms and replication fork stability.

Free Research Field

分子腫瘍学

Academic Significance and Societal Importance of the Research Achievements

ATRX変異は予後不良な神経芽腫(NB)でしばしば見られる。本研究から、ATRXがゲノムの完全性を維持していること、ATRX欠損神経芽腫細胞の複製ストレスによるDNA傷害が、TP53欠損によりDNA修復機構と複製フォークの安定化により緩和されること、その機構にFANCD2タンパク質が主要な役割を果たすことが示された。このことから、FANCD2がATRXが欠損した神経芽腫に対する治療標的となりうることが示唆された。このように本研究の成果から、神経芽腫の腫瘍発生におけるATRX遺伝子変異の意義についての理解が深まり、高リスク神経芽腫に対する個別化医療のための重要な知見が得られた。